Bag filling machine



1955 F. F. LINDSTAEDT ET AL 2,725,168

BAG FILLING MACHINE Filed Oct. 11, 1952 2 Sheets-Sheet 1 ILL 57. Z

4 29 3 3/ 3 INVENTORS 33 Frank E Ling/skied? .'.E' z.g.3 A770 NEY Nov. 29, 1955 F. F. LINDSTAEDT ET AL 2,725,168

BAG FILLING MACHINE Filed Oct. 11, 1952 2 Sheets-Sheet 2 IN V EN TORS Frank E Llhdsfaedf Fred. 5. Wrigh? United States Patent BAG FILLING MACHINE Frank F'. Lindstaedt, San Anselmo, and Fred S. Wright, Sonoma, Calif.

Application October 11, 1952, Serial No. 314,316

13 Claims. (Cl. 226-49) The present invention relates to improvements in a bag filling, weighing and sealing machine, and is directed principally to further developments in the Bag Filling and Weighing Machine described in Patent No. 2,546,193, issued to Frank P. Lindstaedt and Charles R. Fischer, and in the Bag Sealing Machine described in Patent No. 2,571,460, issued to Frank F. Lindstaedt and Charles R. Fischer.

In the former patent, the bags were picked up by ,a suction arm from a stack and telescoped over a chute depending from a hopper, into which weighed quantities of material, such as potato chips were discharged for delivery into the bag, whereupon the bag was dropped to be car ied away by any suitable means.

In. the second patent, the filled bags were placed manually upon a conveyor, were gripped between confronting stretches of two belts and are then successively folded, re-folded, heat-sealed and cooled.

In the present invention, it is proposed to combine the (W0 machines into one unit and to arrange the parts in such a manner that the two confronting belt stretches of the Sealing machine grip the bag directly from underneath the hopper without any intervening manual operations.

In order to allow of this direct removal of the filled bag from underneath the hopper by the belt stretches, it became necessary to dispense with the telescoping of the bag upon the hopper chute, and it is one of the objects of the present invention to provide means for supporting the bag underneath the hopper in such a manner that the bag remains clear of the hopper at all times.

It is a further object of our invention to provide a novel and improved means for successively moving the individual bags from a stack to a position directly underneath the hopper, without opening the bag while in transit.

Another object of the invention is .to provide means for opening the bag while disposed underneath the hop per for receiving a load from the latter and to then again close the bag while the latter is freely suspended.

It is a further object .of the invention to provide a pair of gripping belts having confronting stretches and 'to arrange the latter in such a manner that the confronting stretches grip the filled bag and carry it through the sealing portion of the machine.

It is still further proposed to provide certain refinements in the arrangement of the gripping belts to cause the latter to smooth out the bag material and to prevent tearing of the latter.

Further objects and advantages of our invention will appear as the specification proceeds, .and the new and novel features of our machine will be fully defined in the claims attached hereto.

The preferred form of our invention is illustrated in the accompanying drawings, forming part of this application, in which:

Figure 1 shows a top plan view of the essential part of the machine, with the bag disposed underneath the hopper in open position Those particular portions of 2,725,168 Patented Nov. 29, 1955 the machine of no particular interest for the present invention, such as the weighing apparatus and the sealing apparatus, have been omitted; 7

Figure 2. shows a similar view of the left-hand portion of the machine, with the bag in closed position and in the act of being gripped by the belt stretches Figure 3, a section taken along line 33 of Figure 1;

Figure 4, a detail view, in side elevation and partly in section, of a bag pick-up used in our machine;

Figure 5, an end view of the pick-up;

Figure 6, a partial top plan view of the pick-up shown in, Figure 5; and

Figure 7, an end view of the pick-up arm in horizontal position.

While We have shown only the preferred form of our invention, we wish to have it understood that. various changes or modifications may be made within .the scope of the claims hereto attached, without departing from the spirit of the invention.

Referring. to the drawing in detail, the dotted circle shown at 1 represents the bottom of the hopper, which is fixedly mounted and which receives weighed quantities of material in successive order. The weighing and hopperfeeding apparatus is not illustrated in the drawing, and may be of any desired and preferred type. It may correspond substantially to that described in the Patent No. 2,546,193, or preferably to that described in the co pending application, Serial Number 345,776, filed March '31, 1953.

The present invention is directed primarily to the feeding of the bags to the hopper and the removal of the bags from the hopper.

The hopper .1 and the entire operating mechanism are supported on a suitable horizontal frame 2 having a pair of side members 3, suitable cross-members 4, and suitable leg-supports (not shown).

The bags 5, which preferably are made of a waxed or cellophane paper, and present two adjacent flat sheets cut even .at the top, are disposed on the magazine 6, which latter is mounted on the outside of the frame, sidewise of the hopper and at a considerable distance below the same. The transverse centerline of the magazine is disposed in the central traverse plane of the hopper, and the magazine is made to slant downward slightly in the direction of the hopper.

The magazine has a flat bottom 7, side walls 8 and a front wall 9 to retain the bags in place, the latter having their open ends presented toward the vertical axis of the hopper.

A shaft 10 is supported in the frame, in bearings 11 over the front portion .of the magazine, and at an elevation slightly below that of the discharge end of the hopper and has an arm 12 projecting downwardlytherefrom, the arm being hollow and being connected to suction and suction relief tubes 13 and 14 respectively.

The lower end of the arm has a pick-up tube 15 slidable therein, movement of the pick-up tube being limited by a suitable pin and slot arrangement 16-17. The bottom of the pick-up tube terminates in a suction head 18 extending transversely with respect to the bags and pre- Senting two perforated suction faces 19 adapted to contact the uppermost bag near opposing side edges thereof. The suction faces slant upward, from their inner to their outer edges, as shown, to slightly bend the picked up bag and to prevent the bag from opening while it is carried away.

The suction head has a pin 20 secured thereon which is engageable in a catch 21 mounted on the arm 12 for normally holding the suction head in the raised position shown in Figure4 in dotted lines. The catch is mounted on the free end of a leaf spring 22 and releases the pin when striking a fixed stop 23 on the downward .swing of the arm, so as to cause the suction head to drop on the stack of bags.

When the suction head rises to the dotted line position, it strikes a sliding rod 24 which'operates a switch 25 to set in motion a suitable agency for turning the shaft to swing the arm 12 sidewise into horizontal position. The overall length of the arm 12 and the retracted suction head is equal to the distance between the shaft 10 and the center of the hopper, so that a bag picked up by the suction head will land directly underneath the center of the hopper, as shown in Figure 2.

When the bag reaches this position, it is acted on by two suction fingers 26 for opening the bag. These two fingers are mounted on opposite sides of the bag, in alined relation, and have suction faces 27 confronting the bag. Each of them is pivoted upon two parallel rods 28, which in turn are pivoted to fixed transverse frame member 4, as at 29.

The outer rods 23 are drawn toward one another by a spring 30, and the inner rods may be urged apart by means of a cam 31 operating on rollers 32 carried by brackets 33 mounted adjustably on the rods. The cam is operated by a piston rod 34 reciprocable in the cylinder 35 by pressure applied through tubes 3637.

When the bag reaches its position underneath the hopper in closed condition, the two suction fingers 26 occupy the position shown in Figure 1. At that time, suction is applied to the fingers through tubes 26 and the cam 31 is retracted to allow spring 30 to urge the fingers toward the bag. It should be noted that the degree of advance of the finger toward the bag can be controlled exactly by the cam. This is important because, for a later step in the process, it is desirable that the fingers do not close upon the bag entirely, so as to clamp the bag faces upon one another, but merely make a light contact just enough to attract the sides of the bag by suction.

After the fingers have engaged opposite sides of the bag, they are spread by a forward movement of the cam 31 to present an open bag to the hopper, as shown in Fig ure 1.

The bag is then filled from the hopper with a predetermined weight of material, such as potato chips, and the cam is then again retracted to allow the fingers 26 to move toward one another for closing the bag. At this time the filled and closed bag is freely suspended from the suction ends'of the two fingers 26, the arm 12 having returned to its original position, at the exact time when the suction fingers grip the bag.

Next, the filled bag is gripped by two endless belts 38, only the forward portions of which are shown in Figure l. The rear portions are guided over suitable pulleys (not shown) in a conventional manner, and the belts are made to present extended confronting stretches 39, the extreme forward ends of which are adapted to close in on the near edge of the bag, as in Figure 2.

The front portions of the belts are arranged, however, so that they can spread to form a V-crotch 40 between the same. This is accomplished by providing a pair of intermediate pulleys 41 which are fixed and bear upon the confronting stretches at a certain distance from the extreme forward portions, while the latter are trained over a set of extra pulleys 42 mounted upon the free ends of links 43 pivoted co-axially with the pulleys 41. The two links may be operated for swinging toward or away from one another by means of piston rods 44 actuated by pressure means in the cylinders 45.

The free ends of the arms 43 have short projections 46 carrying spring fingers 47, which latter are positioned to cause the finger tips to close in on the rear portion of the bag while the belts close in on the front portions of the bag. In actual practice, it is desirable to keep the belts stationarywhile the front portions close in on the front portions of the bag because this allows a firm grip to be obtained before the bag is moved forward and tends to smooth out any wrinkles which mayhave developed in the upper portion of the bag in preceding operations.

The fingers 26 will maintain suction contact with the bag until the latter is being gripped between the belt stretches, at which time suction is released immediately, and the fingers are retracted. Since the suction fingers do not clamp upon the bag, the belts have no difiiculty in advancing the bag as soon as suction is released.

The belts carry the bag through sealing apparatus, including preferably folding means, re-folding means, heat sealing and cooling means. This apparatus may be constructed as shown in Patent No. 2,571,460, or in any other suitable manner, and forms no part of the present invention.

The operation of our machine may be explained as follows:

When the arm 12 has reached its horizontal position for placing a bag underneath the hopper, a cam 50 on shaft it! strikes the two switches 51 and 52. The switch 51 operates the cam 31 to retract and to allow the spring 30 to move the suction fingers 26 toward the bag. Switch 52 applies the vacuum to the suction fingers. Application of the suction, releases, through a diaphragm not shown, the operating means for the arm 12 to allow the latter to drop back into vertical position. At the end of this motion, the catch 21 strikes the stop 23 to release the sliding tube 15 and to allow the latter to drop upon the uppermost bag.

The application of the vacuum to .the suction fingers also operates, through the same diaphragm, the rod 34 in the cylinder 35, to advance the cam for opening the bag. The latter is then filled. After the filling of the bag, a suitable agency, not shown, operates the piston rod 34 to again retract and to cause the suction fingers 26 to close the bag. The same agency causes the confronting belt stretches 40 to close in on the bag, and also causes the belts to momentarily stop during the gripping action.

The closing in of the belt stretches operates a switch, not shown, which releases the vacuum in the suction fingers and also operates the piston 34 to spread the fingers. The belts then carry off the bag.

As the belt stretches close in on the bag, they operate another switch (not shown) which applies suction to the picker arm and the suction faces 19 on the uppermost bag. The latter bag closes the suction faces and causes the suction to lift the tube 15 to the dotted line position. The cross-head 18 then strikes the rod 24 which operates switch 25 to set in motion agencies, not shown, for swinging the picker arm into horizontal position to place the new bag underneath the hopper.

We claim:

1. In a machine of the character described, a hopper for delivering material, means for supporting a stack of bags horizontally below and laterally of the hopper, with the intake ends of the bags directed toward the vertical axis of the hopper, suction means for picking a bag from the stack and means for moving the suction means to position the bag underneath the hopper, with the intake end presented upwardly.

2. In a machine of the character described, a hopper for delivering material, means for supporting a stack of bags horizontally below and laterally of the hopper, with the intake ends of the bags directed toward the vertical axis of the hopper, suction means for picking a bag from the stack, means for moving the suction means to position the bag underneath the hopper with the intake end presented upwardly, and suction means for opening the bag to receive material from the hopper.

3. In a machine of the character described, a hopper for delivering material, means for supporting a stack of bags horizontally below and laterally of the hopper, with the intake ends of the bags directed toward the vertical axis of the hopper, an arm swingable over thestack having suction means for picking a bag from the latter, and means for swinging the arm to position the bag underneath the hopper, with the intake end presented upwardly.

4. In a machine of the character described, a hopper for delivering material, means for supporting a stack of bags horizontally below and laterally of the hopper, with the intake ends of the bags directed toward the vertical axis of the hopper, an arm swingable over the stack having suction means for picking a bag from the latter, means for swinging the arm to position the bag underneath the hopper, with the intake end presented upwardly, and suction means for opening the bag to receive material from the hopper.

5. In a machine of the character described, means for supporting a stack of bags horizontally, an arm swingably mounted over the stack, and a member slidable in the arm and having suction means at the lower end thereof for picking a bag from the stack, the suction means comprising a transverse member having suction faces at opposite ends thereof to engage the bag at spaced points and the bags being stacked with their intake ends presented in the direction of the swinging movement.

6. In a machine of the character described, means for supporting a stack of bags horizontally, an arm swingably mounted over the stack, and a member slidable in the arm and having suction means at the lower end thereof for picking a bag from the stack, the suction means comprising a transverse member having suction faces at opposite ends thereof to engage the bag at spaced points, and the suction faces being inclined in opposite directions to have a bending effect on the bag whereby opening of the latter is prevented.

7. In a machine of the character described, means for supporting a stack of bags horizontally, a suction arm mounted over the stack with freedom of swinging motion from a horizontal to a vertical position, a member slidable in the arm and having suction faces at the lower end thereof, means normally locking the member in raised position, means operable to release the locking means for dropping the suction means upon the bags when the arm reaches a vertical position over the bags, and means operable for applying suction through the arm and the said member to the suction faces whereby the uppermost bag is attracted to the suction faces and is made to close the same so as to cause continued suction to raise the said sliding member to its original position.

8. In a machine of the character described, means for supporting a stack of bags horizontally, a suction arm mounted over the stack with freedom of swinging motion from a horizontal to a vertical position, a member slidable in the arm and having suction faces at the lower end thereof, means normally locking the member in raised position, means operable to release the locking means for dropping the suction means upon the bags when the arm reaches a vertical position over the bags, and means operable for applying suction through the arm and the said member to the suction faces whereby the uppermost bag is attracted to the suction faces and is made to close the same so as to cause continued suction to raise the said sliding member to its original position, the locking means being operable to automatically lock the sliding member in raised position.

9. In a machine of the character described, a hopper for delivering material, means for positioning an unopened bag underneath the hopper in upright position, and suction means active on opposite sides of the bag for opening the latter, the latter means comprising a pair of tubes, linkage supporting the tubes on opposite sides of the bag in alined relation and with freedom of movement toward and away from the bag, cooperative cam and spring means active on the linkage for operating the tubes, suction faces at the ends of the tubes confronting the bag, and means for applying suction to the faces as they approach the bag for gripping the sides of the bag and for spreading the same as the tubes retreat from the bag the cam and the linkage having adjustable means for limiting the approach of the tubes toward one another.

10. In a machine of the character described, a hopper for delivering material, means for positioning an unopened bag underneath the hopper in upright position, and suction means active on opposite sides of the bag for opening the latter, the latter means comprising a pair of tubes, linkage supporting the tubes on opposite sides of the bag in alined relation and with freedom of movement toward and away from the bag, cooperative cam and spring means active on the linkage for operating the tubes, suction faces at the ends of the tubes confronting the bag, and means for applying suction to the faces as they approach the bag for gripping the sides of the bag and for spreading the same as the tubes retreat from the bag, and the suction means being operable to close the bag after the same has been filled.

11. In a machine of the character described, a hopper for delivering material, means for positioning an unopened bag underneath the hopper in upright position, suction means active on opposite sides of the bag for opening the latter for filling and for again closing the bag after filling, and means active on opposite sides of the bag for carrying off the bag, the latter means comprising a pair of endless belts having confronting stretches mounted in alinement with the upper portion of the bag, with the front ends of the stretches adapted to partly overlap the bag, and means normally separating the front ends of the stretches operable to close the said front ends upon the bag for carrying away the bag when the confronting stretches are moved away from the original position of the bag.

12. In a machine of the character described, a hopper for delivering material, means for positioning an unopened bag underneath the hopper in upright position, suction means active on opposite sides of the bag for opening the latter for filling and for again closing the bag after filling, and means active on opposite sides of the bag for carrying off the bag, the latter means comprising a pair of endless belts having confronting stretches mounted in alinement with the upper portion of the bag with the front ends of the stretches adapted to partly overlap the bag, and means normally separating the front ends of the stretches operable to close the said front ends upon the bag for carrying away the bag when the confronting stretches are moved away from the original position of the bag, the operating means for the front ends of the belts including a pair of cooperative spring fingers closing in on the far end of the bag while the confronting front ends of the belts close in on the near end of the bag.

13. In a machine of the character described, a pair of endless belts having confronting stretches mounted in adjacent relation for gripping and advancing the upper end of a bag therebetween, a pair of fixed pulleys having intermediate portions of the confronting stretches trained thereover, a pair of links pivoted coaxially with the said pulleys, a second pair of pulleys revolvable in the free ends of the links and having front portions of the belts trained thereover, and operating means for the links adapted for swinging the pulleys of the second pair toward and away from one another, the links having spring fingers mounted thereon in spaced relation to the pulleys of the second pair and movable therewith the spring fingers having free ends turned toward one another and adapted to line up with the confronting stretches when the pulleys of the second pair are swung toward one another.

References Cited in the file of this patent UNITED STATES PATENTS 699,133 Allis May 6, 1902 1,086,631 Weaver Feb. 10, 1914 1,195,229 Johnson Aug. 22, 1916 1,248,856 Henry Dec. 4, 1917 1,589,800 Frank June 22, 1926 2,051,483 Jones Aug. 18, 1936 2,526,543 Davies Oct. 17, 1950 

